Expedition 372B/375 methods

Wallace, Laura; Saffer, D. M.; Barnes, Philip M.; Pecher, Ingo; Petronotis, K. E.; LeVay, Leah J.; Bell, Rebecca; Crundwell, Martin P.; Oliveira, Christie Helouise Engelmann de; Fagereng, Åke; Fulton, P. M.; Greve, Annika; Harris, Robert N.; Hashimoto, Yoshitaka; Hüpers, Andre; Ikari, Matt J.; Ito, Yoshihiro; Kitajima, H.; Kutterolf, Steffen; Lee, H.; Li, X.; Luo, Min; Malie, P.R.; Meneghini, Francesca; Morgan, Julia K.; Noda, Atsushi; Rabinowitz, H. S.; Savage, H. M.; Shepherd, Claire L.; Shreedharan, Srisharan; Solomon, E. A.; Underwood, Michael B.; Wang, M.; Woodhouse, Adam; Bourlange, S.; Brunet, Morgane; Cardona, Sebastian; Clennell, Michael B.; Cook, A.; Dugan, Brandon; Elger, Judith; Gamboa, Davide; Georgiopoulou, Aggeliki; Han, S.; Heeschen, Katja; Hu, Gao; Kim, G.Y.; Koge, Hiroaki; Machado, K. S.; McNamara, David D.; Moore, G. F.; Mountjoy, Joshu; Nole, Michael; Owari, S.; Paganoni, M.; Rose, Patricia M.; Screaton, E.; Shankar, Uma; Torres, Marta E; Wang, X.; Wu, H.-Y.

doi:10.14379/iodp.proc.372b375.102.2019

Cited by 24 publications

(64 citation statements)

References 101 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Biostratigraphic datums are given in Table T4, the distribution of planktonic foraminifer taxa is given in Table T6, and planktonic foraminifer abundances and indications of oceanicity (qualitative measure of the extent to which the paleoenvironment recorded by the faunal assemblage represents open ocean conditions relative to a nearshore-influenced environment) and paleowater depths are given in Table T7 and shown in Figure F14. Absolute ages assigned to biostratigraphic datums follow those listed in Table T4 in the Expedition 372B/375 methods chapter (Wallace et al, 2019).…”

Section: Foraminifersmentioning

confidence: 99%

“…Samples 375-U1526A-1R-CC, 0-5 cm, through 3R-1, 54-56 cm (0.0-19.94 mbsf ), are assigned a Holocene to Middle Pleistocene age (Haweran to Castlecliffian; 0-0.63 Ma) based on the abundance of predominantly dextral coiled populations of Truncorotalia truncatulinoides and the presence of Hirsutella hirsuta in Sample 3R-1, 54-56 cm (19.94 mbsf ) (see Biostratigraphy in the Expedition 372B/375 methods chapter [Wallace et al, 2019]). The identification of Holocene strata in Hole U1526B (see below) indicates a sedimentary hiatus between the Holocene and Middle Pleistocene.…”

Section: Hole U1526amentioning

confidence: 99%

“…Archive halves were measured with a spacing of 2.5 cm. The superconducting rock magnetometer (SRM) has a response curve with a half-width of ~4 cm (see Paleomagnetism in the Expedition 372B/375 methods chapter [Wallace et al, 2019]), which limits the clast size that can be successfully resolved based on the SRM data. We thus collected 14 discrete samples from individual clasts/basalts in the volcaniclastic sequences of Lithostratigraphic Unit II (see Lithostratigraphy) to better resolve the remanence directions from individual clasts, their alteration and/or oxidation state, and their emplacement temperatures.…”

Section: Paleomagnetismmentioning

confidence: 99%

“…Headspace samples were taken from each sediment core to monitor for the presence and abundance of C 1 -C 3 hydrocarbons as part of the standard safety protocol (Pimmel and Claypool, 2001). A total of 13 headspace gas samples were analyzed by gas chromatography (see Geochemistry in the Expedition 372B/375 methods chapter [Wallace et al, 2019]), and no methane, ethane, propane, ethene, or propene were detected (Table T10). Figure F23.…”

Section: Gas Analysesmentioning

confidence: 99%

“…Organic C values, calculated as the difference between TC and carbonate C content (see Geochemistry in the Expedition 372B/375 methods chapter [Wallace et al, 2019]), are low in Lithostratigraphic Units I and II (ranging from 0.00 to 0.61 wt%). The highest values are shallower than 21 mbsf and correspond to calcareous mud.…”

Section: Bulk Sediment Analysismentioning

confidence: 99%

See 4 more Smart Citations

Site U1526

Wallace¹,

Saffer²,

Petronotis³

et al. 2019

Proceedings of the International Ocean Discovery Program

Self Cite

View full text Add to dashboard Cite

This work is distributed under the Creative Commons Attribution 4.0 International (CC BY 4.0) license. Contents 1 Background and objectives 3 Operations 4 Lithostratigraphy 9 Biostratigraphy 11 Paleomagnetism 14 Structural geology 16 Geochemistry 18 Physical properties 20 Core-seismic integration 25 References L.M. Wallace et al. Site U1526 IODP Proceedings 3 Volume 372B/375 Operations Transit to Site U1526 The vessel arrived at Site U1526 at 1700 h (UTC + 12 h) on 22 April 2018. Upon arrival, the thrusters were lowered, and the dynamic positioning (DP) system was engaged. Hole U1526A A rotary core barrel (RCB) bottom-hole assembly (BHA) was assembled, and the drill string was lowered to the seafloor. Hole U1526A (39°1.3203ʹS, 179°14.7594ʹE; 2890.1 meters below sea level [mbsl]; Table T1) was spudded at 0150 h on 23 April 2018. Cores 1R-14R advanced from 0 to 83.6 meters below seafloor (mbsf) and recovered 29.26 m (35% recovery). Nonmagnetic core barrels were used for all cores. At the completion of coring, the drill bit was partially raised from the seafloor, and the ship returned to nearby Site U1520. Hole U1526B On 2 May 2018, we returned to Site U1526 following an 8 h transit from Site U1520 in DP mode. The ship was offset 20 m westnorthwest from Hole U1526A, and Hole U1526B (39°1.3146ʹS, 179°14.7481ʹE; 2888.4 mbsl) was spudded at 2015 h on 2 May. Advanced piston corer (APC) Cores 1H-4H and extended core barrel (XCB) Core 5X advanced from 0 to 33.5 mbsf and recovered 31.56 m (94% recovery). Nonmagnetic core barrels were used for all APC cores. The total time spent at Site U1526 was 2.88 days.

show abstract

Section: Foraminifersmentioning

confidence: 99%

Section: Hole U1526amentioning

confidence: 99%

Section: Paleomagnetismmentioning

confidence: 99%

Section: Gas Analysesmentioning

confidence: 99%

Section: Bulk Sediment Analysismentioning

confidence: 99%

See 3 more Smart Citations

Site U1526

Wallace¹,

Saffer²,

Petronotis³

et al. 2019

Proceedings of the International Ocean Discovery Program

Self Cite

View full text Add to dashboard Cite

show abstract

Ultra‐long Duration of Seismic Ground Motion Arising From a Thick, Low‐Velocity Sedimentary Wedge

et al. 2019

Self Cite

View full text Add to dashboard Cite

Sedimentary basins are known to amplify and increase the duration of ground motions that accompany earthquakes. A similar phenomenon is expected, but not as well documented, in low seismic-velocity accretionary prisms along subduction margins. In this study, we report anomalously long duration of long-period ground motions observed in the North Island of New Zealand during seismic wave propagation from the M7.8 Kaikoura earthquake ∼600 km away. Unique waveform data captured by strong-motion, high-rate GPS and ocean bottom pressure sensors reveal that long-period ground motions lasted longer than 450 s in the northeastern North Island. These waveforms indicate one of the longest durations of long-period (>10 s) ground motions ever recorded at similar epicentral distances for comparable, large earthquakes. To understand the underlying mechanism, we use numerical simulations of seismic wave propagation. We find that a velocity model that includes an accretionary prism, modeled as a large-scale (∼30,000 km 2 ) wedge characterized by extremely low seismic wave speeds, can explain the observed long durations of long-period ground motions as the reverberations of seismic waves within the low-velocity wedge. We show that the long duration of long-period ground motions leads to prolonged dynamic stressing on the plate interface, likely accentuating the triggering of slow slip that occurred following the Kaikoura earthquake. Accretionary prisms characterized by extremely low seismic velocities may enhance the generation of tsunami earthquakes and dynamic triggering of slow slip events observed in the northern Hikurangi and other subduction margins.

show abstract